So are you actually going to answer his question, or are you planning to play word games all day like last time you were here?
Before this thread I don't recall issuing any opinion about the "show me one structural engineer" question, but ok, I at least will give a point to that side: they found a structural engineer who questions the events of 9/11 and I will make no presumptions good or bad on this fellow's qualifications.
I still say, so what. The evidence is still absolutely overwhelming that two planes struck WTC 1 & 2 and the damage and resulting fires lead to their collapse, that fire and falling debris caused the collapse of WTC 7, that another plane struck the Pentagon and a fourth crashed in PA. I have seen no physical evidence that brings any of that into question.
I think the important thing to understand is that getting a qualified engineer is the beginning of good research, not the end of it.
Now that they have a qualified engineer, we can all hope to see coherent engineering arguments that are consistent with the high quality of analysis we rightly expect from engineers.
Whatever the quality of his analysis, we can engage it on scientific and engineering terms. We can use the vocabulary of engineering to discuss this engineering problem with him.
And, obviously, if he does not engage the problem as an engineer, then it doesn't really matter if he's an engineer or not.
Architect, your list looks complete to me. On a couple of the points, my 2 cents worth.
4. Jet fuel is an accelerant and burns off fairly quickly, leaving a normal "basic" office fire. However steel is a heat sink, and takes a long time to heat up to the point of failure.
That "basic" office fire simply did not progress the way a 'normal' office fire would, that is to say starting in one small arae and getting slowly larger. It started large and moved to new fuel areas as well.
Once again I must ask , if steel is such a good conductor of heat that a "basic" office fire could not produce enough heat to cause the structural members of a building to rise to a temp that would seriously compromise it strength then why do steel structural members of buildings require fire insulation to be in place? Are fire codes simply too strict?
5. Pancake collapses are not applicable to steel structures, being primarily related to concrete raised slab construction with shear failure at the column connections.Once the collapse process had been initiated, "you could say anything". He doesn't seem to be saying there's anything suspicious apart from the initial collapse.
That struck me as well. However he does go on about the concrete turning to dust and that it would require explosives to do that. I calculated the TNT equivalent that would be required to theorectically accomplish a pulverisation of all the concrete into fine dust. If I find where I posted it I'll post it hee as well but IIRC it comes to a few million pounds of TNT. So Pegalow must then be saying that an enormous amount of explosive power was used for this.
He also notes that the structure was welded, not bolted, beforegoing on to state that we should have instead seen deflection and settlement but not such a quick collapse unless you took out all the columns at the same time.
So how much deflection could a column take before fracturing? I await his paper that will show the math on his claims.
7. These buildings are designed with huge safety factors. a major issue here is the imposed wind loadings, and he understands that the buildings were designed to accommodate constant wind speeds of 90mph, gusting to 140mph. This means it was able to resist a horizontal load of around 10 million lbs (do none of you Yanks use metric, for heaven's sake?).
They survived their horizontal loading well. That is to say that the plane's impact did not send them toppling over. What does that have to do with their vertical strength though? Last time I looked they came down as vertical structural members failed.
Physicists use more SI, engineers use more Imperial measurements.
Hmmm, I posted it on the apollohoax board. However, i was approaching it from Hoffman's 90% energy deficit mode.
Hoffman does his calculations and comes up with an energy availability that is, in his calculations, only one-tenth that required to do what was shown to happen(in his view of what happened).
Ok, so then if there was only one tenth the energy required due to gravity AND the other 90% of the energy came from explosives then what are the calculations on the amount of explosives required to contribute 9 times as much energy than was available due to gravitational potential.
Hoffman states that 4 x 10^11 joules of energy would be available due to gravity. 9 times that is 36 x 10^11 joules.
TNT has 4.18 x 10^6 joules/Kg therefore it would require the equivalent to 861,244 kilograms(1,894,737 pounds) of TNT in addition to the gravity energy in order to do what Hoffman states happened.
Now C4 which is 18% more powerful that TNT would of course use less(C4 is 91% RDX) so that would be the equivalent of 1,605,709 pounds of C4(802 tons)
The premise is then that more than one million pounds of explosives were surreptiously installed in the steel and concrete of the WTC towers prior to 9/11. That dentonators and control devices were attached to the explosives as well. That these explosives were somehow protected from prior discovery, and premature destruction or detonation due to the plane impacts and subsequent fires, and that they all functioned perfectly on 9/11/01.
It is no wonder that Hoffman does not do these calculations and include it in his conclusions. Any scientific theory must be falsifiable. that is that it should stand up to other approaches to the same question. If Hoffman's calculations are correct then 1.6 million pounds of C4 or other explosives equivalent are required. However, such an amount being used brings up too many hard questions for Hoffman to bother with so he ignores it.
The number of trucks delivering goods to the towers daily is not quite valid. You would be unloading the entire contents of 25 - 35 large semi-trucks. Such would not be a normal sight and if smaller trucks were used then more of them would be required. It is simply unbelieveable IMHO that this activity would go completely unnoticed. Remember that this would not only have to be overlooked but be so invisible that no one has recalled such a level of activity even after the theories about planted bombs has come out.
mini-nukes would present many problems, and who says that a fusion bomb would not produce radioactive by products?
If all of the explosive power is contained in one device , where was it placed? Certainly not at the impact zones. It would have been very obvious for one thing and one would have to be able to pinpoint that zone before the planes hit and do so with +/- one floor accuracy. A nuke explosion would propagate at the speed of sound(or greater) but it takes sound a lot less time to travel the 1000 feet or so from the impact zone to the ground than even the 10 seconds we keep hearing about as the time it took to collapse the entire building. There is NO evidence of a supersonic shock wave travelling the length of the towers.
I see that Gordon Ross in his paper states that ;
A considerable amount of energy would be required to pulverise the concrete into the fine
dust which was evident from the photographic and other evidence. To quantify this energy it is
necessary to use the fracture energy value, but this has a variable value dependent on, among
other factors, the size of the concrete piece, and its constituents, most notably, aggregate size.
There is no typical value. In order to assess the energy consumed I will refer to the work of Dr.
Frank Greening . It should be noted that Dr. Greening, like Dr. Bazant, does not, as yet,
support the contention that the tower collapse was caused by anything other than the damage
caused by aircraft impact and subsequent and consequent fires. The tower, using Dr. Greening’s
figures, contained approximately 50000 tonnes of concrete, and the assumption is made that only
10% of this was pulverised to a size of 60 micrometres. One kilogram of concrete at this particle
size will have a surface area of 67 m2. We can now use Dr. Greening’s figure for concrete
fracture energy of 100J/m2 to show that the energy requirement for one floor would be
50*106kg / 110floors * 67m2 * 100J/m2 * 10% = - 304 MJ.
304MJ X 110 floors= 33400 MJ required to pulverise 10% of the concrete.
Using my figures above for the energy released by TNT that comes to a requirement of over 8000 Kg of TNT with 100% efficiency to do that job. That is still 8 tons. However, Pegalow and Fetzer comment that there were NO large chunks of concrete, that all of the concrete was pulverised, not just the 10% that Greening and Ross use. So we now need over 70 tons and that explosive power must still be utilised in such a way as to have all of its power go into the pulverisation of the concrete. Such a placement would require that these explosives be placed within the concrete and that their original purpose is indeed the pulverisation of the concrete. I can't think of why sucha thing would be required by the architects of sucha plot but let's ignore that for a while. If the explosives were 10 times as powerful as TNT we are back to 7 tons of it but if only 75% of the released power actually manages to go into the pulverisation of the concrete (I believe that I am being generous here) then we go back up to about 9 tonnes of explosives.
That is 9 tonnes of explosives, embedded throughout the concrete of the buildings installed and detonated in such a way(timing issues) as to allow the greatest use of its power in pulverising the concrete, not only on floors below but also those on and above the fire floors.
oh, and no one noticed anyone hammering holes in the floors to install this.
There's a discussion going on over at the LC WTC forums about "explosive concrete" being used in the tower construction...some sort of explosive mixed in with the concrete during the pour. It also mentions the use of explosive (C4) treated rebar in the reinforced concrete. All from eyewitness accounts during construction. This is their possible explanation for the concrete to dust problem.
...and they are dead serious in discussing this.
As an aside, I'm something of a Mt St Helens watcher. When that mountain blew in '80, the force of the gravity driven landslide alone was sufficient to turn a fair portion of the mass to dust, and it was a lateral slide. It was described as almost a "liquification". I can only imagine the energy of the vertically collapsing towers would have a similar effect, albeit on a very small scale by comparison.
There was a lot of "security clearance" stuff going on as the building was going up...
It's all there, I can't make this up...
And, construction on the towers started in 1966; the first was occupied in 1970, the second in 1972. That means someone planned the towers' destruction over 30 years in advance... before Al Qaeda was started and before Hussein came to power.
Never attribute to malice that which can be adequately explained by ignorance or stupidity.
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I'm afraid that this theory has been around for some time , and yes, it is said by the people who promote it, to be standard construction practise. The reasoning goes , ' the building will have to be demolished at some time in the future so in order to facilitate this the explosives are planted in the building during construction'.
I dearly hope that few who subscribe to it manage to procreate.
This kind of thing just makes me sick. Just imagine the thousands of workers to take part in the initial construction and numerous renevations done over the years, particularly those after the bombing in '93. The amount of pride and satisfaction they must have felt over the successful completion of such a revolutionary building and the absolute devastation when those long, proud years of backbreaking work were destroyed in less than 90 minutes by a group of religious extremists bent on mass murder. The notion that these competent and proud professionals could all be involved in a conspiracy as bizarre and downright sick as mixing explosives into concrete being poured for a commercial building intended to accommodate tens of thousands of people every single day is not only so beyond rational argument as to be absurd. What a misery the lives of those whose mindset can even imagine such widespread duplicity must be.There's a discussion going on over at the LC WTC forums about "explosive concrete" being used in the tower construction...some sort of explosive mixed in with the concrete during the pour. It also mentions the use of explosive (C4) treated rebar in the reinforced concrete...
If Composition C-4 coated rebar is a "standard practise" then they [those who make the claim] should be easily able to produce people who can testify that they actually applied the explosive to the rebar in preparation for use in reinforced concrete. It should be no trouble at all.
"Standard practise" implies in general use. Not special purpose. Not special circumstances, but in general use. Since rebar is used in a lot of concrete construction, a LOT of people would be involved. It would show up in construction specifications, among other places.
Epoxy or other coatings on rebar are used to retard corrosion or improve bond between the rebar and the concrete and is a fairly common use (I believe) but not necessarily universal. Whether that is used will depend on the conditions that the rebar and the reinforced concrete will face.
Composition C-4 is a maleable material (hence the term "plastic explosive") which when subjected to the effects of having concrete poured, manipulated, and pushed around would likely easily be scraped right off.
If thinking of the eventual building demolition -- a thin layer of C-4 on rebar might cause some separation but I would think there would be severe problems in propagation of the explosion along the rebar of the concrete. With a thin layer (an inch or two maybe) of concrete between each rebar, the detonation of C-4 along one rebar might not be enough to reliably set off the C-4 on a nearby rebar. One might also consider that if the initial shot does not bring down the building that it has potentially become a much more dangerous place to enter. Better to drop it properly than fiddle with emplacing a military explosive years to decades in advance of the eventual demolition in some half-baked idea that it will make the CD easier.
According to the Wiki article, C-4 is 1.36 times as explosive as TNT.
C-4 cannot be set off by fire. My dad, and many others in Vietnam used to used it to cook.
My dad has spent a great many years in various roles of concrete freeway construction. In the modern operations, the concrete is mixed in a batch plant that is high enough enough to scare B-1 pilots on training runs when the plant is erected overnight. The ingredients are added by machine, so it might be possible, in the modern version of things, to add something to one of the ingredients and have none of the workers actually know what's in there.
The part that would be difficult here, is that concrete is a lot like baking. Everything ha to be added in the right ratio, or it doesn't work. If the paving boss says it's too wet, the plant operator will scale back the water a bit. If the ratios are too far outside of accepted norms, someone will notice. This means that the explosive used would have to have the same consistency as whatever it gets mixed into. If it's in the sand, then it needs to be just about like sand.
Also, the explosive would have to be something that did not detonate when a core sample was taken to test the strength, something the state inspectors do. It would also need to not go off if the need arose to knock out a part with a jackhammer or similar.
Do they explain how the explosives were set off? Maybe even why they didn't go off when the initial impact took place?
I'm Not Evil.
An evil person would do the things that pop into my head.
Consider it the other way. If we use it all the time for tall buildings, then they'll have no problem coming up with conclusive physical evidence then?
If C-4 coated rebar is common practise then they should have no problem producing a length of it and detonating it for all to see.
For that matter they should be able to point out structures that have already been brought down using this preplanted explosive rebar or concrete. We can then ask the demolition company directly what explosives were used and where they were installed and when.
Why do I think that if it were me asking those questions I would get a roll of the eyes from the person I was speaking to?
Because that exploding concrete is top secret and nobody should know which buildings are prepped.
You would think they would modernize the office building system so it was more like the self-destruct on Star Trek, but WTC was an old building.